Phosphorus compounds



Patented Oct. 28, 1 941 Ernest F. Engelke, Merchantville, N. 1., assig'norto Cities ServiceOil Company, New York, N. Y... a corporation of Pennsylvania No Drawing. Original application May a, 1939,-

Serial No. 272,489. Divided and this application January 19, 1940, Serial No. 314,605 v 12 Claims. i]. 260-125) This invention relates to new phosphorus compounds for use as oil addition agents and for various purposes in the arts. More particularly the new phosphorus compounds comprise certain phosphorus condensation products especially adapted for use as lubricants generally and for manufacturing various types of film agents. I

This application is a divison ofpending appli= cation Serial No. 272,489, filed May 8, 1939, for Oil addition agents."

strength A number of organic phosphorus compounds use in have been proposed for the load-carrying caparticularly to increase pacity as described, for example, in Klemgards Luof the oils, and for certain other purposes,

lubricating oils,

bricating Greases: Their Manufacture and Use,"

pages 748 to 751, published in 1937. Moran et al., in U. S. Patents Nos. 2,058,342 to 4, has proposed the use of certain phosphites in corrosive lubricating oils, to prevent corrosion of certain types of bearings. Other patents have described the addition of certain other phosphorus organic compounds to lubricating oils.

The primary object of the present invention is to provide new and useful phosphorus organic compositions which are stable and which maintain a very tenacious film on the part or parts to be lubricated.

Another object of the invention is to provide an improved phosphorus organic composition as an addition agent which can be used in relatively small proportions in lubricating and other oil products to improve such products, andwhich will provide a lubricating film under conditions where such film could not be Y products to which the composition is added..

A further object of the invention is to provide an improved process for manufacturing the phosphorus organic compositions of the present invention.-

, Accordingly, the present invention contemplates an improved composition as an addition material such as a film strength agent and comprising a phosphorus condensasulfur is directly attached to phosphorus.

maintained by the adapted for use tion product produced by a condensationreaction which includes the sulphurization of a quantity of phosphine under certain preferred conditions. The sulphurized condensation product formed in accordance with the present invention may be used alone as a film strength agent or mixed with any grade. of lubricating oil, hydrocarbon, mineral oil or oily or grease compositions. The phosphines used in preparing the condensation product of the present invention ortho compound.

may be primary or secondary, but are preferably the symmetrical tertiary phosphines in which I three organic groups are attached to phosphorus. These groups or radicals, each of which may be representedby (R) or (R0), may be aliphatic, aromatic, mixed aromatic and aliphatic, heterocyclic or hydroaromatic groups. The R groups in any phosphine may be alike or different, but in general the-O-phosphines are preferred, ,s'uchastricresol-O-phcsphine, (ROMP. Oine-or more of the R" groups in the phosphin'e'may behalogenated. In fact, it has been found that the halogenated phenolic phosphines produce a much more 'efiective film strength agent'tha'n the .unhalogenated compounds. Like or unlike phosphines may be condensed.

The efiectiveness of the improved condensation products of the present invention as film strength agents for example, may be illustrated by. re-

ferring to the following specific examples, in

which the percentages given areby weight.

" Example I The film strength agent-used in this example was made by taking a quantity of tri -orthocresol-O-phosphine, (CIhH4CsO) 3F. and addin to it one half the atomic equivalent of flowers of sulfur. The resulting mixture was heated to a temperature of from 370 to 380 F. 'where an exothermic reaction takes place, by which, according to tests which have been made, a sulphurized condensation product is formed in whichthe The particular manner in which the phosphine molecules are condensed is not known, but they are believed to be condensed on a sulfur atom to form a sulfide containing at least twoof the phosphine groups. The sulfur may act as a condensing agent.

The sulfide condensation product produced by the foregoing procedure was mixed .with 20 SJLE. lubricatingv oil in the proportion of 1% of the condensation product. This mixture may be made while the filin strength agent is still hot after the condensation reaction. This oil product had a load-carrying capacity of 12,500 lbs. per

square inch'on the Timken lubricant testing machine, whereas the original oil had only 7,800 lbs. Sulfur condensation products of the type described above have also been made from meta and para cresol-O-ph'osphines, but have'slightly lower load-carrying capacity than that made from the Example II I The condensation product used in accordance 400 F. was prevented. The resulting condensa-- I tion product contains relatively large molecular combinations of at least two molecules of the phosphine, with sulfur directly attached to phosphorus.

The condensation product made in accordance with this example was dissolved in 20 S.A.E. lubricating oil stock in the proportion of 1% to give a lubricant composition having excellent loadcarrying qualities. This product showed a loadcarrying capacity of 25,500 lbs. per square inch on the Timken testing machine.

Example III The condensation product used in accordance with this example was made in somewhat the same manner as those of Examples I and II, but a greater proportion of sulfur was employed. Accordingly, a quantity of tri-ortho cresol-O-phosphine was mixed with one and one half atomic equivalents of flowers of sulfur, and, reacted at "a temperature of from 400 to 415 F. Here again the reaction was exothermic and a very heavy product produced. At minus 10 F. the product was a stiff, clear gel, but -at high temperatures it blends directly with mineral oils. Three tenths of 1% of the condensation product was blended with 20 S.A.E. lubricating oil stock to give a .lubricant which showed a load-carrying capacity of 18,300 lbs. per square inch'on the Timken testing machine. When 1% of thecondensation product was used, the load-carrying capacity was considerably above that of the lubricant prepared in accordance with Example II.

The proportion of the product used in oilv compositions may vary from 0.25% to 5%, but about 0.5 to 1.5% is preferred for most purposes.

An attempt was made to form condensation products containing greater proportions of sulfur, but, with the general procedure employed, it was found impossible to make a product containing a greater proportion of sulfur than three atomic equivalents of sulfur to two molecules of the phosphine. In each case, the excess sulfur could be crystallized out by chilling the reaction mixture to F. and allowing it to stand. However, when an excess of sulfur was employed above the proportion referred to, only the excess could be crystallized out. v

The structure of the condensation products produced in accordance with the present invention is not known, but they appear to be compounds containing at least two molecules of the phosphine derivative in which the phosphorus atoms are combined with sulfur and/or each other in a complex polycompound. The condensation reactions may involve interoxidation reduction reactions between the phosphorus atoms of the phosphines and the sulfur atoms. Various theories and structural formulae might be suggested as to the actual condensation products formed in view of various tests and analyses made on the reaction products described in the also contains, besides the isomeric cresols, several or all of the isomeric xylenols although in much smaller proportions, may be used. The O-phosphines prepared from these raw materials and sulphurized by the procedure given in the examples gave film strength agents having loadcarrying capacities varying between 20,000 to 32,000 lbs. per square inch.

The preferred addition agent in accordance with the present invention is that produced by the proportions of phosphine and sulfur used in Example I. This agent appears to have an unusual corrosion inhibiting action as well as a relatively high load-carrying capacity. The proportions of sulfur and phosphine used in accordance with Example I may be varied from one to eight atoms of sulfur to ten molecules of the phosphine. Where, however, the load-carrying capacity of the lubricant to be made is of primary importance, the sulfur condensation prod-'- uct is preferably made in accordance with Example III, so that the proportion of sulfur in the compound, to phosphorus, is as great as possible.

The organic phosphine used for making the condensation product in accordance with the present invention is preferably one in which the organic radical (R) is attached to phosphorus through oxygen (R0) and contains an aromatic or cyclic hydrocarbon group such as the'benzene ring; also one in which the organic radical contains one or more halogen atoms such for=example as chlorine.

While certain organic phosphites have been suggested by others as corrosion inhibitors in lubricating oils, repeated tests have shown that the phosphine sulfide condensation product formed in accordance with Example I is even more effective as a corrosion inhibitor. For example, the loss by corrosion of a Pennsylvania S.A.E. 20 mineral oil on a cadmium-copper silver hearing was 6.2 mgms., while the same oil containing only 0.25% of the condensation product of Example I showed a loss of only 0.5 mgm. In a comparative test, the' same sample containin tricresol phosphite showed a loss of 1.6 mgms.

While the foregoing examples illustrating the application of the improved compositions relate foregoing examples, but such theories are not regarded as of any importance to the invention.

In the place of tri-ortho-cresoL-O-phosphine, phosphines prepared from commercial phenol mixtures such as termed "mixed cresols containing ortho, meta and para cresols in varying proportions, or commercial cresylic acid which primarily to the use of the compositions in mineral oils, it is to be understood that the invention contemplates their use as such for all purposes to which they are adapted, for example in cutting oils and in lubricants for the lubrication of bearings and cylinder wall surfaces of internal combustion engines. The compositions may also be used as antioxidants; as an antirust agent, and as a film strength agent in greases and for blending with fatty oils, synthetic oils and esters, .or used alone as film strength agents for any desired use where the maintenance of a surface film between moving-parts of a mechanism is essential. The improved composition of the present invention has been found to be particularly useful in the crank case of an automobile, since in a lubricant vehicle the material maintains a'relatively clear oil over substantially long periods of use. The composition has also been found of particular advantage in the removal of old resinous deposits from the parts of the motor. The composition is an eifective constituent therefore of a crank case flushing composition, not only because it helps to dissolve the resinous constituents in the motor and crank case, but because it provides an effective lubricant in light oil solvents or mixtures, so that the motor may be operated for a substantial period of time while The condensation product of the present inve'ntion may be used as a top cylinder lubricant in an internal combustion engine by adding approximately 1% by volume of the product to the motor fuel to be used in the engine. The improved product or products of the present invention may be employed for other purposes as will be apparent to those skilled in the art.

Having thus described the invention in its preferred form, what is claimed as new is:

1. A condensation product of organic phosphine groups with sulfur.

2. A condensation product adapted for use as an addition agent comprising essentially an aryl-O-phosphine condensation product containing sulfur chemically combined with the phosphorus of at least two phosphine groups.

3. The method of manufacturing a phosphorus and sulfur-containing agent for addition to oily compositions, which comprises mixing sulfur with an organic phosphine in the desired proportions, heating the resulting mixture to a temperature of from 370 F. to 415- F., thereby condensing the phosphine in the presence of the sulfur and combining the sulfur in the resulting condensation product. 7

4. A condensation product formed by condensing an organic phosphine in the presence of sulfur to chemically combine the sulfur in the resulting condensation product. p

5. A condensation reaction product of sulfur and an aryl-O-phosphine in which at least two phosphine groups are combined.

6. A condensation reaction product of sulfur and an aryl-O-phosphine in which at least two phosphine groups are linked to each other through a sulfur atom.

7. A condensation reaction product of sulfur and a phenolic phosphine in which at least two phosphine groups are linked together through the phosphorus of the phosphine groups.

8. A corrosion inhibitor comprising essentially an organic phosphine condensation product in which at least two organic phosphine groups are condensed with a sulfur atom.

9. A condensation product of an organic phosphine with sulfur in which the ratio of sulfur to organic phosphine is from one to eight atoms of sulfur to ten phosphine groups. l

10. A condensation reaction product of sulfur and a tricresol-O-phosphine in which the phosphine groups are linked together through sulfur.

11. A condensation reaction product of sulfur and a halogenated aryl phosphine in which at, least two phosphine groups are linked to each. 

